We marvel daily at the blossoming of new renewable technologies. Their promise of a low-carbon economy gives us optimism, and their downright coolness makes our synapses jittery with excitement. Earth: The Sequel is a deep dive into the most groundbreaking and enticing new modes of harvesting energy. Thin-film solar and flying wind turbines are just the beginning. Authors Fred Krupp (president of Environmental Defense) and Miriam Horn gave TreeHugger an exclusive interview about this new book and its message of hope and prosperity. ::TreeHugger Radio

Listen to the podcast of this interview via iTunes, or just click here to listen, right-click to download.

Full text after the jump. TreeHugger: First off, Fred tell me this, why the sequel? What was episode one and what's coming next?

Fred Krupp: Well, episode one is Earth—what we know—and what we know unfortunately is melting glaciers and rising sea levels, dying coral reefs, and strengthening hurricanes. The idea behind "The Sequel" is what happens next. And what happens next is this abundance of alternatives as we innovate our way out of the mess.

TH: You compare progress in a lot of these industries to what has happened in the microprocessor industry, or the Internet. You draw a connection to Moore's Law, whereby processor speed doubles about every 24 months, and this has been responsible for a lot of remarkable changes we have seen. Clearly this is fast progress, so paint this picture for me: 10 years from now, what will be the average American experience in terms of energy, where will her power come from, what will her home energy system look like, will she plug in her computer, will she pay an energy bill?

A rendering of what Ausra expects its one-square-mile field of mirrors to look like.

Fred: Ten years from now I don't think we will be completely transitioned, but I think we will be well along the way. And I would predict that in 10 years it is going to depend on where you live. In a populous sunny state like California, homeowners probably will be getting lots of electricity from their solar roofs. In the southwest, in the desert, energy might be served up by a solar thermal power plant with the advantages that it is easier to store energy in hot water than it is in electricity.

And in the northwest, a wave energy plant could be generating electricity. In the northeast it may be that a new national renewable grid is serving up renewable energy from some of those same sources. So we could be well along in 10 years, but I don't think the transition will be complete in 10 years.

TH: What you are describing in a sense hints at a distributed network of energy rather than a centralized system. Using different technologies based on the locale, the environment, the resources available, is the shift from centralized to distributed infrastructure, is this a major component of renewable energy?

Fred: I think one of the advantages of renewable energy is that they can be generated, they will able to be generated in smaller amounts without the big centralized plants. It will give us an advantage in terms of redundancy in case of a failure or, God forbid, terrorist attack, but it also will give us an advantage in terms of less losses over the transmission lines that we now experience.

But I think that in ten years we will still be burning a lot of coal. But by then I think we will be capturing carbon-dioxide from a significant amount of coal and burying that underground. We have such a big installed coal base that even if we don't build new coal power plants, we are going to need to capture the CO2 from a lot of those plants and within ten years I think that will be happening.

TH: Miriam, you were doing a lot of this research face to face with these remarkable entrepreneurs who are doing stuff that most people can just dream about, revolutionizing the energy industry. And there is this guy up in Alaska, he is using geothermal, and he actually has an ice castle. Can you tell me about this man?

An underwater turbine that gathers energy from tidal motion.

Miriam: Yes, that was by far the most fun trip in writing the book. Bernie is an eccentric character. You will never meet another person like him. I describe him as being like an impresario of another age. His hero is Walt Disney. He spent 30 years working in recycling. He says other people mine the stuff out of the earth and he goes and mines what everybody else has already mined.

And he bought a hot springs resort. It is very popular with Japanese tourists because it is on the auroral oval, which is the best place on earth to watch the aurora borealis. And Bernie was spending a fortune on diesel. He is off the grid, so he was trucking in diesel and spending $1,000 a day to power the resort.

And he also got this idea that he wanted to build an ice hotel and there are few in the world, but he wanted to build the only one in the world that was going to be standing even in the summer. And of course in the summer in Alaska the sun never goes down and it gets to be about 85 or 90 degrees. So Bernie built his ice hotel and created this diesel-powered refrigeration system and the sun came out in June and started beating down on it and the whole thing melted. And Forbes declared it the dumbest business idea of the year.

He decided he was going to do it again because that is the kind of guy Bernie is, but his wife told him he got one more chance. So he knew he had to get it right this time. In the interim he had hired this woman engineer named Gwen, who also happens to be a dog musher and has several times finished both the Iditarod and the Yukon Quest.

And Gwen had been talking to him about tapping this amazing geothermal resource they have. So they have the hot springs, but they have a hot springs that is not very hot. And every where in the world right now that geothermal energy is being created, they use extremely hot water and they need a big differential between the hottest hot and the coldest cold.

And a number of very smart people told Bernie that you can't do it, your water is not hot enough and you don't have a big enough temperature differential. But Bernie doesn't necessarily get dissuaded by experts telling him he can't do something and so he and Gwen with the help of a nuclear physicist went ahead and designed the first-ever refrigeration system that was able to use a temperature differential as small as he had. And they rebuilt the ice hotel, they redesigned the cooling system, they used this geothermal chiller. And that ice hotel is still standing.

I got to go in it and lie on the ice bed with the caribou hide. They serve you martinis in glasses carved from ice. There are Japanese tourists lined up to get inside. Bernie is no longer spending any money on diesel.

The photovoltaic installation at Nellis Air Force Base.

TH: And that all came from trying to keep the ice hotel from melting. Let's talk about the force that melts the ice. Fred, solar electric or photovoltaic technology is good now, but it's not great. The efficiency of a solar panel is still rather low, the payback is long, and mostly it's only affordable with subsidies added on. But you say that this is changing pretty fast. What's next for solar?

Fred: Well, what's next for solar is that a lot of the people who have been building computer chips have realized that solar cells are also made out of silicon. They've applied some of the best technology and most current technology to make more efficient and cheaper cells.

So we've already seen real fortunes made in solar. First Solar is now a $16 billion market cap company. The late John Walton's investment in that company has grown by about twenty-fold, so his estate has profited by several billion dollars. But there are many companies now all working on this problem of making solar cells more efficient and cheaper.

One of the stories we tell in the book is of Conrad Burke at InnovaLight, who has figured out how to use cheap silicon instead of the expensive stuff. Instead of having to compete with the shortage that there now is to make computer chips, he's figured out a way to use the cheap, unpurified stuff and paint it on to metal.

So if you can imagine a printing press being fed with flexible metal instead of paper, that is how he's stamping solar cells onto metal. It saves a lot of money because then instead installing a solar panel box of glass on top of a roof, the solar cell is the roof. There are many innovations like this that are now burgeoning.

TH: Tell me about wave power. You investigated some people who are doing things that capture the enormous energy that comes from tidal forces. Tell me about that.

Miriam: Tidal and wave are considered two different directions in maritime energy, and we looked at both. The tidal company that we looked at is Verdant Power right here in New York. They have been putting turbines that look like underwater windmills into the East River and capturing the tides. They work in two directions so that you get the energy both of the outgoing tide and the incoming tide.

A number of companies are beginning to explore the energy potential in these various tidal flows. Voight Siemens is doing an absolutely enormous tidal project in South Korea that will be hundreds and hundreds of megawatts. They suspend their turbines on a kind of revolving bridge, so the turbine drops into the water and then twice a day as the tide shifts, it lifts out and the whole thing revolves and drops back in again.

They're able to borrow a lot of the technology that has already been developed for wind, which has been working for 30 years. The Environmental Defense Fund just hosted a whole group of people working in wave and tidal energy who are being very proactive about making sure that they are environmentally sensitive in the way that they develop it: that they don't chop up fish, that they don't disturb sensitive bottoms.

With wave energy they're actually harvesting the energy of the up and down motion of the waves themselves. We went out to the northwest tip of the continental United States in the Olympic peninsula and visited with a tribe of Indians, the Macaw Indians, who are working with a company called Finavera on a project called the Aqua Buoy.

The Aqua Buoy looks like a navigational buoy; it sits on the top of the water. But suspended from its bottom is a long, pretty low-tech hose pump. It's a big long hose that gets stretched and released by the rising and falling of the buoy. It compresses water, which gets pushed through a turbine to power a generator. Then that electricity gets carried back by a cable to the land. It's a really interesting partnership in large measure because of the involvement of this Indian tribe who's been there for 2,000 years. They've always relied on the sea to sustain them and now this is a new way that they've found for the sea to sustain them.

Finavera's rendering of an 80 megawatt array of AquaBuOYs.

TH: Before we started you were talking about how the two of you have been traveling around promoting the book. You've met with the policy people, you've met with the business people, you've met with the tech people; and you said that people are still surprised that you're not peddling a doom and gloom approach. It's still taking people off guard that this is a message of hope and optimism and profitability. So this image of "The Sequel," you are clearly very hopeful.

Fred: That's right. I think for both Miriam and I, the process of writing this book has made us, if anything, more hopeful. But yes, people are surprised. They expected maybe another global warming book about the grave stakes. And the stakes are grave, but the book turns out to be about hope and optimism and invention and ingenuity and entrepreneurialism and capital markets and commerce and profit. Yeah, lots of profit.

And those are words that they are surprised to hear from, especially from me—I'm an environmental lawyer running one of the country's well-respected environmental advocacy organizations. I think they may be expecting a talk about policy. And I love legislation and government, make no mistake: government has the key supporting role to play here by enacting a hard cap on carbon on global warming pollution. But they don't have the starring role. The starring role belongs to American commerce, beginning with inventors and their new ideas, and the risk-taking entrepreneurs who will launch the startups, and the successful ones that will develop into small companies and the really successful ones that will have IPOs like First Solar.

And this story, this America-rises-to-the-challenge story, is the sequel. Because we are not doomed, we will get out of this fix. I think what has surprised people is they find global warming so overwhelming, they haven't yet seen past that to the fact that we will create a viable future.